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Q & A: Photographing a heat source such as a volcano

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Most recent answer: 05/07/2012
Q:
according to quantum mechanics, measuring the temperature of lava from a distant volcano by photographing it's color with a telescoping camera has an effect on the temperature on the lava or does not have an effect on the lava?
- paulina (age 22)
des plaines,il, USA
A:
Hi there,
There should be no effect on a heat source by photographing  it.   A body at a given temperature is always emitting photons according to quantum mechanical black-body radiation described by Planck's Law.  When you capture these photons, as in a telescope or photograph, they come for free.  If you didn't nab them they would continue on and on, until something else did. 

LeeH

(published on 05/07/2012)

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